1. Field of the Invention
The present invention relates to an LED module and an LED lighting device.
2. Description of the Related Art
FIG. 23 shows an example of a conventional LED module (see, for example, JP 2002-314136A). An LED module 900 shown in FIG. 23 includes a wiring board 100, a plurality of LED chips 200, a drive IC 300 and a heat dissipation plate 400. The heat dissipation plate 400 is made of a material having excellent thermal conductivity and has an elongated plate shape. The wiring board 100 is provided at each longitudinal end of the underside of the heat dissipation plate 400. The LED chips 200 are provided in a region extending from the longitudinal midway portion of the surface of the heat dissipation plate 400 to a position toward each longitudinal end, and aligned in the longitudinal direction of the heat dissipation plate 400. The drive IC 300 has a constant voltage circuit, a light modulation circuit and the like, and is provided at the longitudinal midway portion of the underside of the heat dissipation plate 400. The LED chips 200 are driven and controlled by the drive IC 300 and emit light upward. The heat dissipation plate 400 dissipates heat generated during operation of the LED chips 200 and the drive IC 300 to the outside.
In the LED module 900, the LED chips 200 and the drive IC 300 are arranged so as to overlap at the longitudinal midway portion of the heat dissipation plate 400. Accordingly, the temperature near the midway portion of the heat dissipation plate 400 tends to be higher than that near the ends. The LED chips 200 are more likely to emit a reduced amount of light or modulated color light as the temperature increases. Therefore, in the LED module 900, there is a possibility that variations might occur in the amount of light and color in the longitudinal direction.